1) Field
The general inventive concept relates to a touch panel having an infrared sensor.
2) Description of the Related Art
A touch panels is a type of user interface that is generally disposed on a display device to detect a touch point based on a change in an electrical characteristic caused by contact of a hand or stylus, for example, which touches the touch panel. The touch panel is often used in devices such as compact portable terminals and office equipment.
Generally, the touch panel includes a transparent substrate, infrared (“IR”) light emitting diodes (“LEDs”) and an IR sensor array. The touch panel is operated by supplying IR rays from the IR LEDs to the transparent substrate and receiving the IR rays, which pass through the transparent substrate, with the IR sensor. However, when the transparent substrate is touched, IR rays that pass through a corresponding portion the transparent substrate are scattered and, as a result, the IR sensor does not receive the IR rays that are scattered. Thus, a position corresponding to the portion at which the IR rays are not received (due to the scattering) may be incorrectly recognized as a touch point.
The touch panel is generally included in a touch display system, and, more particularly, the touch panel is typically disposed on a display device, such as a cathode-ray tube (“CRT”) monitor or a liquid crystal display (“LCD”), for example. The touch panel generally has a separate IR filter, disposed near an upper portion of the IR sensor, to improve a function of the IR sensor and a reliability of recognition of the touch point.